Helicopter landing mat



Jan. 12,1960 F. E. LINGAFELTER 2,920,846

HELICOPTER LANDING MAT Filed Sept. 7 1955 1 I I 1 o o o o 0 o o O 15 INVENTOR.

United States Patent HELICOPTER LANDING MAT Fred E. Lingafelter, Mansfield, Ohio, assignor of onethird to Avery C. Hand, Jr., Mansfield, Ohio Application September 7, 1955, Serial No. 532,860

Claims. (Cl. 244-114) This invention relates to a landing device for helicopters, and in particular it relates to a landing device which is constructed of readily portable sections so thatit may be easily moved to any desired location.

.The use of helicopters in heavily built up areas often requires that the roof of a building be used as a landing site; and this originally required a specially constructed roof formed of several layersof heavily reinforced concr'ete or the like to support the weight of the helicopter.

Many original roof constructions would be adequate as helicopter landing areas if there were any effective means for spreading the weight of the helicopter over a large portion of the roof area, instead of concentrating the weight on the small surface area actually contacted by the skids or wheels of the craft.

In accordance with the present invention, a helicopter landing area is formed by using a large fluid filled mattress on top of which is supported a landing platform for the. helicopter. For lightness and low cost the mattress will ordinarily be filled by inflating it with air; but it is obvious that for reduced weight the mattress might be inflated with helium or other light gas; or under special conditions where weight is not a factor it might be filled with a liquid or liquid and gas. compressibility and light weight make gas preferable to liquid; while availability and cost factors make air the preferred gas. The inflated mattress serves to distribute the Weight of the helicopter substantially uniformly over the entire roof area beneath the mattress. Thus, a 10 x 20 foot landing device constructed in accordance with this invention would distribute the weight of a 10,000 pound helicopter soas to produce a pressure on the building of only about 50 pounds per square foot, which is less weight per square foot than that of 150 pound man standing. Many adequately constructed roofs can carry a gross load of 10,000 pounds without any difllculty, but cannot support such a weight if it is concentrated in the small surface area of the conventional helicopter landing gear.

In order that the device of the present invention may be readily portable, and may be used to construct a landing area of any desired dimensions, it is preferably made up of a plurality of identical mattress members and a plurality of identical platform members. The mattress members may conveniently be connected by means of a fluid tube so that they may be inflated through a valve and so that changes in fluid pressure may be distributed uniformly throughout all the mattresses forming the area; and the platform members are preferably interlocked so that they provide a continuous landing surface.

The invention is illustrated in a preferred embodiment in the accompanying drawings, in which:

Fig. l is a perspective view of a building roof which has been converted to a landing area by the use of the invention;

Fig. 2 is a plan view of a landing area made up of four identical mattress members and platform members;

Fig. 3 is an enlarged fragmentary plan view at the intersection between two platform members;

Fig. 4 is an enlarged fragmentary section taken as indicated along the line 4-4 of Fig. 2; and

Fig. 5 is a fragmentary section on'an enlarged scale taken as indicated along line 5-5 of Fig. 3.

Referring to the drawings in greater detail, and referring first to Fig. l, a building B has a roof R which is provided with a helicopter landing device indicated generally at 10 which is made up of a plurality of identical sections each of which is indicated by the reference numeral 11.

Referring now to Figs. 2-5, each of the units 11 includes a mattress member 12 and a platform member 13 which is supported on the mattress member. As best seen in Figs. 4 and 5, a mattress member 12 has a top wall 14, a bottom wall 15 and four-side walls 16, and is provided with spaced vertical internal perforated membranes 17 and a horizontal perforated membrane 18 which control the shape of the inflated mattress. The mattress 12 is made of inextensible air tight limp sheet material such as a vinyl plastic or rubber impregnated fabric. The arrangement of the internal perforated membranes 17 and 18 is such that when the mattress is inflated the top wall 14 and bottom wall 15 are substantially parallel and generally flat. The term generally flat as used herein does not, of course, rule out surface irregularities such as the corrugations which may be formed along the lines wall provide a generally continuous surface upon which the platform member 13 may rest with its weight distributed generally evenly over the mattress surface, and similarly the bottom wall 15 need only distribute its own weight and the weight supported on it generally uniformly over the roof upon which the mattress is placed.

Preferably the mattress members 12 are identical 10 X 10 ft. sq. members about 8 inches thick, and each mattress member is provided at opposite ends with fluid tube connector nipples 19, the nipples 19 being positioned close to the diagonally opposite corners of the mattress members. With this arrangement of the fluid tube connector nipples 19 the mattresses may be arranged in parallel rows and all of the mattresses in one row may be connected with one another by fluid tube connectors 20 each of which is fastened into the connector nipples 19 of two adjacent mattresses in the row; and the adjacent end mattresses in adjacent rows may be connected by a laterally extending connector tube 21 which is secured to the connector nipples 19 in the coplanar end walls of the two laterally adjacent mattresses. The end mattress in one row may be supplied with a valve 22, which is fastened into the connector nipple 19, and the last mattress in the last row may be provided with a plug 23 which is fastened into the connector nipple 19.

As best seen in Figs. 3,5, each platform member '13 may be a corrugated sheet of lightweight metal such as aluminum or magnesium; or if the stresses which may be encountered are too great for sheet metal the platform member may be in the form of a cast metalgrating, or possibly the combination of corrugated sheet metal with cast stiffening ribs. not important so long as the platform has the necessary strength and rigidity to form the landing surface. of the platform members 13 is slightly larger than each of the mattress members 12 so that two adjacent platform members 13 may meet between the spaced margins of a pair of mattress members 12 and may be interlocked to hold them together as seen in Figs. 3 and 5. The in- The specific surface construction is Each pins are not desirable any other convenient interlocking arrangement may be adopted.

Since the platform does not float in a liquid, it need not, be provided with any liquid tight compartment, and the platform merely rests on the mattress; thus permitting a much lighter and less expensive platform construction than would be afforded by a pontoon floated in a tank of water.

To set up a helicopter landing area on any suitable roof, a desired number of mattress members 12 may be arranged in parallel rows as seen in the drawings and may be connected by connector tubes 20-and 21. A mattress at an end of an outside row is provided with a valve 22, while the corresponding mattress in the opposite end row is provided with an air plug 23. When the mattresses are filled to any desired degree and the platforms 13 are placed on the mattresses and interlocked with one another the landing area is ready for use. The platforms may be positioned on top of the mattresses either before or after the mattresses are filled.

The construction of the mattresses and the platform in convenient units which may be readily transported from place to place provides a very adaptable structure. Obviously, the location of a helicopter landing area constructed in accordance with the present invention may be other than a roof. Thus, for example, a landing area may be set up in a sheltered bay or river, or even at the edge of an area of swamp which would otherwise be useless for helicopter operation. It is even possible that by appropriate construction of the individual mattress andplatform units the pilots and crew of a pair of helicopters under emergency conditions could lay. down a landing area for themselves on Water.

It is obvious that the device of the present invention may be used as a landing area for any air craft which land and take off generally vertically, or with only a very short run. Thus, the term helicopter is used herein as exemplary of one known type of air craft with which the invention may be used.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitation should be understood therefrom as modifications will be obvious to those skilled in the art.

I claim:

1. A portable landing device for helicopters comprising: a plurality of readily portable fluid filled mattress members which have fluid tight walls of limp sheet. material, and substantially fiat top and bottom surfaces, said mattress members being positioned with their adjacent side margins in spaced relationship to one another and the total. horizontal area covered by said mattress members being suflicient to provide a landing area for a helicopter; a valve member in a wall of one of said mattress members; fluid tube means affording communication between all said mattress members; and a plurality of readily portable rigid platform sections supported on said mattress members with their adjacent side margins substantially abutting one another to provide an effectively continuous landing platform, whereby the weight of a helicopter resting on said landing platform is carried by the mattress means and is distributed effectively uniformly over a surface upon which the mattress members rest.

2. The device of claim 1 in which each mattress member is rectangular and has two fluid tube connector nipples at opposite ends each adapted to receive an end of a fluid tube, the fluid tube means extends between adjacent connector nipples, and the valve member is mounted in one of said connector nipples.

3. The device of claim 1 in which the mattress members are rectangular and are positioned in parallel rows, there is a fluid tube connection from each mattress member to the next mattressmember in the same row and from an end mattress, member in tahrow to, the laterally adjacent mattress member in the next row.

4.. A portable landing device for helicopters comprising: a plurality of readily portable identical, rectangular fluid filled mattress members which have fluid tight walls of limp sheet material and substantially flat top and bottom surfaces, said mattress members being positioned 1n parallel rows with their adjacent side margins in spaced relationship to one another and the total horizontal area covered by said mattress members being sufficient to provide a landing area for a helicopter; a valve member in a wall of one of said mattress members; fluid tube means affording communication between all said mattress members; and a plurality of readily portable rigld platform sections supported on said mattress members with then adjacent side margins abutting and interlocked with one another to provide an effectively continuous landing platform, whereby the weight of a helicopter resting on sa d landing platform is carried by the mattress means and is distributed effectively uniformly over a surface upon which the mattress members rest.

5. A roof landing area for helicopters, comprising: a generally planar and horizontal rigid roof; gas filled mattress means of sufficient horizontal dimensions to provide a landing area for a helicopter on said roof, said mattress means having gas tight walls of limp sheet material including a substantially flat top surface and a substan-. tially flat bottom surface in direct contact with a portion of said roof; and rigid, effectively planar landing platform means supported on said mattress means, whereby the weight of a helicopter resting on said landing platform means is carried by the mattress means and is distributed effectively uniformly over that portion of the roof with which the bottom surface of the mattress means is in contact.

6..A roof landing area for helicopters, comprising: a generally planar and horizontal rigid roof; a plurality of readily portable gas filled mattress members on said roof with their side margins adjacent one another, the interiors of all said members being in communication with one another to distribute the pressure of the gas equally among them, each of said mattress members having gas tight walls of limp sheet material providing a substantially flat to psurface and a substantially flat bottom surface in direct contact with said roof, said mattress members covering a section of said roof which is large enough to provide a landing area for a helicopter; and a plurality of readily portable, rigid platform sections supported on said mattress members with their adjacent side margins substantially abutting one another to provide. an effectively continuous and planar landing platform, whereby the weight of a helicopter resting on said landingplatform is carried by the mattress members and is distributed effectively uniformly over that portion of the, roof which is covered by said mattress members.

7. A landing device for helicopters comprising: a plurmity of gas filled mattress members which have gas top and bottom surfaces, said mattress members having tight walls of limp sheet material and substantially flat their side margins adjacent one another and the interiors of all said members being in communication with one another to distribute the pressure of the gas evenly among them; and rigid, effectively planar landing platform means supported on said mattress members, whereby the weight of a helicopter resting on said landing platform means is carried by said mattress members and is distributed effectively uniformly over the area occupied by them.

8. A landing device for helicopters comprising: a plurality of gas filled mattress members which have gas tight walls of limp sheet material and substantially flattop and bottom surfaces, said mattress members having their side margins adjacent one another and the interiors of all said members'being in communication with one another to distribute the pressure of the gas evenly among them; and a plurality of readily portable, rigid platform sections supported on said mattress members with their adjacent side margins substantially abutting one another to provide an effectively continuous and planar landing platform, whereby the weight of a helicopter resting on said platform is carried by said mattress members and is distributed effectively uniformly over the area occupied by them.

9. A roof landing area for helicopters, comprising: a generally planar and horizontal rigid roof; a plurality of gas filled mattress members on said roof with their side margins adjacent one another, said mattress members having substantially flat top surfaces and substantially flat bottom surfaces in direct contact with said roof, said mattress members covering a section of said roof which is large enough to provide a landing area for a helicopter; and effectively planar landing platform means the entire area of which is rigid and the bottom surface of which is in contact with each of said mattress members, whereby the weight of a helicopter resting on said platform means is carried by said mattress members and is distributed effectively uniformly over that portion of the roof which is covered by said mattress members.

10. A roof landing area for helicopters, comprising: a generally planar and horizontal rigid roof; gas filled mattress means of suflicient horizontal dimensions to provide a landing area for a helicopter on said roof, said mattress means having a substantially flat top surface and having a substantially flat bottom surface in direct contact with a portion of said roof; and effectively planar, rigid landing platform'means, the bottom surface of said platform means being in direct contact with the top surface of the rnattress means, and the top surface of said platform means forming the landing surface for a helicopter, whereby the weight of a helicopter resting on said landing surface is carried by the mattress means and is distributed effectively uniformly over that portion of the roof with which the 5 bottom surface of the mattress means is in contact.

References Cited in the file of this patent UNITED STATES PATENTS 1,175,316 Solon Mar. 14, 1916 1,178,421 Smith Apr. 4, 1916 2,453,155 Nelson Nov. 9, 1948 2,636,457 Finley Apr. 28, 1953 2,639,750 Phane May 26, 1953 2,657,884 Merrill Nov. 3, 1953 15 2,681,190 Thomson June 15, 1954 2,850,252 Ford Sept. 2, 1958 FOREIGN PATENTS 21,386 Great Britain 1895 20 247,916 Switzerland Jan. 3, 1948 648,853 France Aug. 20, 1928 6 9 2,329 Great Britain June 3, 1953 741,920 Great Britain Dec. 14, 1955 742,240 Great Britain Dec. 21, 1955 25 906,488 France a May 22, 1945 1,035,755 France Apr. 22, 1953 OTHER REFERENCES Scientific American, vol. CXXIII, No. 14, Oct. 2, 1920, so 114-435. 

